Volcano Types Changing Earth HW # 4 Name: ___________________Use this text and the work from class to answer the questions about different volcano types.

Cinder Cones - Cinder cones are the smallest and most common volcano. They have steep sides like composite volcanoes, but are much smaller, rarely reaching even 300 meters in height. Cinder cones usually have a crater at the summit and are composed of small fragments of rock, called cinders. The cinders are piled on top of one another. These volcanoes usually do not produce streams of lava. Cinder cones often form near larger volcanoes. Most composite and shield volcanoes have nearby cinder cones. Cinder cones usually build up very rapidly & erupt for a short time. Many only erupt once.

Mt. Fuji is a well-known composite volcano.

A cross section of a composite volcano reveals alternating layers of rock and ash: (1) magma chamber, (2) bedrock, (3) pipe, (4) ash layers, (5) lava layers, (6) lava flow, (7) vent, (8) lava, (9) ash cloud. Frequently there is a large crater at the top from the last eruption. Composite volcanoes are common along convergent plate boundaries. When a tectonic plate subducts, it melts. This creates the thick magma needed for these eruptions. The Pacific Ring of Fire is dotted by composite volcanoes.

Composite Volcanoes - Composite volcanoes have broad bases and steep sides. These volcanoes usually have a large crater at the top. The crater was created during the volcano's last eruption. Composite volcanoes are also called stratovolcanoes. This is because they are formed by alternating layers (strata) of magma and ash. The magma that creates composite volcanoes tends to be thick. The steep sides form because the lava cannot flow too far from the vent. The thick magma may also create explosive eruptions. Ash and pyroclasts erupt into the air. Much of this material falls back down near the vent. This creates the steep sides of stratovolcanoes.

Shield Volcanoes - Shield volcanoes look like a huge warrior’s shield laid down. They have a very wide base - much flatter on the top than a composite volcano. The lava that creates shield volcanoes is very thin. The thin lava spreads out. This builds a large, flat volcano layer by layer. Shield volcanoes are very large. The Mauna Loa Volcano has a diameter of more than 112 kilometers (70 miles). The top of nearby Mauna Kea Volcano is more than ten kilometers (6 miles) from its base on the seafloor.Shield volcanoes often form along divergent plate boundaries. They also form at hot spots, like Hawaii. Shield volcano eruptions are non-explosive.Kilauea, a shield volcano in Hawaii.

1. Describe a shield volcano and how it forms.

2. Describe a composite volcano and how it forms.

3. How does the composition of magma affect the type of volcano that forms?

4. Explain why cinder cone volcanoes are not known to get very tall.

Volcano Types Changing Earth HW #4 Name: ___________________Use this text and the work from class to answer the questions about different volcano types.

Match each definition with the correct term.Definitions_____ 1. smallest and most common type of volcano_____ 2. example of a shield volcano_____ 3. volcano with a broad base and steep sides_____ 4. example of a composite volcano_____ 5. volcano that produces so much ash that it blocks the sun_____ 6. volcano that forms a huge, gently sloping mountain

Termsa. cinder coneb. composite volcanoc. shield volcanod. supervolcanoe. Kilaueaf.. Fuji

Fill in the blank with the appropriate term.1 A volcano formed of alternating layers of magma and ash is a(n) __________ volcano.2 __________ volcanoes form from thick lava.3 Composite volcanoes generally have __________ eruptions.4 __________ volcanoes form from thin lava.5 Shield volcanoes generally form along __________ plate boundaries.6 Shield volcanoes generally have __________ eruptions.7 Cinder cones usually have a(n) __________ at the summit.